What does the command name "dd" stand for?
I'm using dd to copy an image onto a USB. But what does dd stand for?
I understand its use, but not what the name dd actually means, or is an acronym for.
It doesn't even say in the man page.
Solution 1:
The syntax was inspired by the DD (data definition) statement of OS/360 JCL. Source:GNU
More Reading Here
Solution 2:
There are many theories. I recall in Unix v7 (when dd first appeared) the man page said it meant disk dump (or was it data dump?) since it was frequently used as a disk backup/restore utility. However, an archive of the v7 man page mentions no etymology nor meaning. Possibly I heard it from someone at Bell Labs since I had occasional access in the early 1980s.
Other theories are:
- data destroyer
- data destructor
- disk destroyer
- delete data
- duplicate data
- originally for Copy and Convert, but was renamed because the C compiler already used
cc(man dd from Unix-V7 on PDP-11)